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Magnetic endoscopic imaging

Adam V Haycock, MD, MBBS, FRCP
Section Editor
Douglas A Howell, MD, FASGE, FACG
Deputy Editor
Kristen M Robson, MD, MBA, FACG


Variations in colonic anatomy can make colonoscopy technically difficult to perform and to teach. In addition, it is not always possible to precisely localize lesions within the colon, information that is important if patients require subsequent endoscopic or surgical therapy.

One method for overcoming these limitations is to provide a view of the colonoscope during the procedure. This was initially done with fluoroscopic guidance, but this approach is no longer used in routine clinical practice because of its inconvenience, added expense, and necessity for radiation exposure. An alternative to fluoroscopy is magnetic endoscopic imaging (MEI), which provides real-time three-dimensional views of the colonoscope shaft configuration and its location within the abdomen. This may aid trainees and less experienced endoscopists as they perform routine colonoscopies and may aid experienced endoscopists during difficult cases.

Issues related to MEI will be reviewed here. Other options for localizing lesions within the colon are discussed separately. (See "Tattooing and other methods for localizing colonic lesions".)


The ability to visualize the shaft of the scope during colonoscopy may be helpful in multiple settings. It may aid the endoscopist during a difficult colonoscopy, it may help with lesion localization, and it may improve the teaching of colonoscopy.

Difficult colonoscopy — Factors that can increase the difficulty of colonoscopy include variations in colonic anatomy, loop formation during instrument insertion, and the presence of abdominal or pelvic adhesions. Increased colonic mobility can predispose to loop formation, whereas adhesions can interfere with normal scope insertion and loop reduction.

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Literature review current through: Nov 2017. | This topic last updated: Apr 21, 2016.
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